DESCRIPTION This is a competitive renewal application for the training program in Environmental Health Sciences of the Johns Hopkins University School of Hygiene and Public Health (SHPH). The program is interdisciplinary and interdepartmental. Twenty pre- and four postdoctoral trainees matriculate into one of four academic departments: Biochemistry, Environmental Health Sciences/Toxicology Division, Epidemiology, or Molecular Microbiology and Immunology. The applicant states that the strengths of the program include: First, that the program resides in a school of public health where emphasis is placed on the application of knowledge of mechanisms of cell processes and toxicity to protection of human health from adverse effects of environmental agents. Second, the research program encompass many disciplines, ranging from studies at the chemical and molecular levels through the cellular level to the use of whole animal models and the study of human populations. Third, a common scientific foundation for the predoctoral trainees is facilitated by a core of focussed courses: "Principles of Toxicology", "Environmental Health", "Cell Biology and Biochemistry", "Public Health Perspectives on Doctoral Research", and "Research Ethics" as well as their active participation in an annual scientific workshop, an event co-sponsored by the Training Program and the Johns Hopkins Center for Urban Environmental Health. The rationale for this laboratory based training program stems from the fact that successful approaches to detection and prevention strategies and the evaluation of risk of exposure must be based on a mechanistic understanding of toxicity. The overall goal of the training program is to provide students with course work and research experiences to enable them to apply the concepts of and techniques of chemistry, biochemistry, cell and molecular biology, immunology, toxicology, and epidemiology to improve our understanding of the mechanisms through which environmental agents may cause adverse effects on human health. An interrelated goal is to expose the students to the real problems in environmental health so that they become aware of the concerns of communities on the adverse effects of environmental exposures. This is accomplished through the unique environment created by the setting, i.e., the presence of the training program in the SHPH, through the core curriculum, and by the participation of the many training faculty and students in the integrative research programs of the Center in Urban and Environmental Health which is also supported by NIEHS. These experiences serve to increase the awareness of the students of the need for the application of their research findings to improve our ability to develop strategies for monitoring exposure, determining risk of exposure, identifying susceptibilities to exposure and devising prevention approaches. Further, these experiences professionally position graduates for productive career positions in academia, industry, and government.